Cotek AD-1500 - Modbus Register; Modbus Function Code Read Coils Registers (0 X01)

4
1-5. Modbus Register
Function Description
Function Code
Read Coils
0X01
Read Holding Registers
0X03
Read Input Registers
0X04
Write Single Coil
0X05
Write Single Register
0X06
1-6. Modbus Function Code Read Coils Registers
(0x01)
The coils in the response message are packed as one coil per bit of the data field.
Status is indicated as 1= ON and 0= OFF. The LSB of the first data byte contains the
output addressed in the query. The other coils follow toward the high order end of this
byte, and from low order to high order in subsequent bytes.
Request Frame:
length
Description
Slave Address
1 Byte
0XA0 (Default Address)
Function Code
1 Byte
0x01
Starting Address MSB
1 Byte
0x00
Starting Address LSB
1 Byte
0x01
Quantity of Coils MSB
1 Byte
0x00
Quantity of Coils LSB
1 Byte
0x01
(number of word to read)
CRC LSB
1 Byte
CRC MSB
1 Byte